A suction cup is widely employed in people's daily life. Different articles, such as safety rail, grab rail, tray, hook, etc., may be firmly attached to a smooth surface, such as a tiled wall surface, via a suction cup to perform their intended functions.
Generally, the suction cup can only be suction-adhered to a tiled or other type of smooth wall surface, and is not provided with any structure to enhance its adherence to the wall surface. Conventional suction cup is subject to loosening, slipping, or even separating from the wall surface when it is used in a wet bathroom, has been used to support a heavy load over a long period of time, or is affected by other external environmental factors. The loosened or slipped suction cup usually looks just as usual before it finally separates from the wall surface, and a user might not be aware of any potential dangers thereof. When a user grips at an article mounted on a wall via a suction cup that has become loosened or displaced, an accident will happen.